Natural freshwater surface streams of considerable volume and a permanent or seasonal flow, moving in a definite channel toward a sea, lake, or another river; any large streams, or ones larger than brooks or creeks, such as the trunk stream and larger branches of a drainage system. [Glossary of Geology, 4th ed.]

The Sacramento-San Joaquin River Delta is the hub of California's water system and an important habitat for fish and wildlife. USGS research has provided resource managers and other stakeholders with a good understanding of how pesticides enter the Delta.

Access to national water resources real-time data typically recorded at 15-60 minute intervals, stored onsite, and then transmitted to USGS offices every 4 hours. Select for site information, ground water, surface water, and water quality.